1. Technical Field
The field of art to which this invention pertains may be generally located in the class of devices relating to valves. Class 137, Fluid Handling, U.S. Patent Office Classification, appears to be the applicable general area of art to which the subject matter similar to this invention has been classified in the past.
2. Background Information
It is known in the valve art to provide solenoid operated two-way, three-way and four-way poppet valves for controlling the flow of fluid, either air or hydraulic oil, to a device which is to be controlled by fluid under pressure, as for example, another valve or a fluid cylinder. A problem encountered in the use of solenoid operated poppet valves is that they require a large solenoid thrust when these valves are used to control high pressure fluids, in order to overcome the large spring pressure required to maintain the solenoid armature in a closed position against the pressure of the fluid. This problem has been partially solved by the balanced solenoid operated poppet valves disclosed in U.S. Pat. No. 4,598,736 which provides for the elimination of the need of a high solenoid thrust in a solenoid operated poppet valve, by the provision of a lower balancing means which balances the solenoid armature. However, the lower balanced type solenoid operated poppet valve disclosed in this patent has a disadvantage in that the lower balancing system employed in those types of solenoid operated poppet valves cannot be efficiently adapted for use in a two-way solenoid operated poppet valve.